Helical ground state and weak ferromagnetism in the edge-shared chain cuprate S.-L. Drechsler, J. Richter, A. A. Gippius, A. Vasiliev, A. A. Bush, A. S. Moskvin, J. Málek, Yu. Prots, W. Schnelle and H. RosnerEurophys. Lett., 73 1 (2006) 83-89DOI: https://doi.org/10.1209/epl/i2005-10356-y